With rapid development of electronic and information industries, computers become essential tools in our daily lives. For example, computers can be used to process data in order to simplify and accelerate the work. Moreover, computers can be used to provide video entertainments. In addition, computers can be connected to the internet to acquire information.
Generally, a power management program is installed in the computer. The time parameters of the power management program in the computer may be adjusted by the user according to the usual practice or the work characteristics of the user. For example, the time parameters include the waiting time of activating a screen saver, the waiting time of turning off the computer screen, the waiting time of entering the system standby, the waiting time of entering the system hibernation and so on. Consequently, after the computer has been idled for a certain time period, the computer enters a power-saving mode.
However, the above power management mechanism is not user-friendly. For example, while an application program of the computer is executed to play a multimedia file or a streaming media data is watched through the internet, the mouse or the keyboard of the computer is usually not used. If the mouse or the keyboard has not been used for a long time, the computer may enter the power-saving mode. For example, in the power-saving mode, the screen saver may be activated. Under this circumstance, the mood of the user to enjoy the multimedia file or the streaming media data is suddenly interrupted. For continuously playing the multimedia file or watching the streaming media data, the user has to move the mouse or press a key of the keyboard.
For solving the above drawbacks, the user may deliberately set a longer waiting time as the time parameter of the power management program or disable the power-saving function. However, after the playback of the multimedia file or the streaming media data is ended, the user usually forgets to set the time parameter of the power management program to the original status or forgets to re-enable the power-saving function.
Accordingly, a power-saving method of a computer is disclosed in Taiwanese Patent No. 413896 for example. In accordance with this power-saving method, an image pickup device is used to capture an image in front of the computer. According to the image, the computer may judge whether the user is in front of the computer. If the user is not in front of the computer to operate the computer, the power-saving function computer is enabled so as to achieve the power-saving purpose. Consequently, even if the work characteristics of different users are different, it is not necessary to adjust the time parameter of the power management program in the computer.
Moreover, in the above power-saving method, the computer may analyze whether there is any facial feature (e.g. an eye, a nose or a mouth) in the image captured by the image pickup device. According to the analyzing result, the computer judges whether the user is in front of the computer. However, since the face recognition technology requires a huge computation data amount, the computing loading of the computer is increased. Moreover, regardless of whether the user is in front of the computer, the computer has to continuously perform the face recognition on the image which is captured by the image pickup device. Under this circumstance, the power-saving purpose fails to be achieved. In other words, the conventional controlling method of the computer screen needs to be further improved.